I just wrap a reflector strip around my left elbow or wrist. I also wear a reflector vest and have reflectors on my ankles too. When I signal left, I'm sure other motorists see me. But I signal only when I see a big gap in my mirror. Too many headlights in the mirror distorts your sense of distance. If I can't squeeze in, I'm not taking the chance. I'd rather turn right and loop around so I can see the traffic directly instead of through a mirror.